public class Test12 {
public static void main(String[] args) {
	String a = "10";
	String b = "15";
	String c = "20";
	String d = "25";
	int a1 = Integer.parseInt(a);               //将字符串转换成整型
	int a2 = Integer.parseInt(b);               //将字符串转换成整型
	int a3 = Integer.parseInt(c);               //将字符串转换成整型
	int a4 = Integer.parseInt(d);               //将字符串转换成整型
	int sum = a1+a2+a3+a4;
	System.out.println("sum="+sum);
}
}
